Base-neutralized reaction products of phosphoric acid with polyether epoxides (E.sup.1) of the nominal formula ##STR1## WHEREIN Q, n, R.sup.1, R.sup.2, r and R.sup.20 are as defined below, have been found to be water-thinnable and to have utility as curable coatings. When a fugitive base is employed to neutralize the acid/epoxide products, the coatings are of particular value as linings for food and beverage cans. The cured coatings are hydrophobic and thermoset.
Q, n, R.sup.1, R.sup.2, r and R.sup.20, in the preceding formula, are defined as follows:
Q, independently in each occurrence, is ##STR2## n is an integer of from 0 to 40, R IS ZERO, 1 OR 2, AND INDEPENDENTLY IN EACH OCCURRENCE, PA1 R.sup.1 is H, methyl or ethyl, PA1 R.sup.2 is --Br, --Cl, or a C.sub.1 to .sub.4 alkyl or alkenyl group, PA1 R.sup.3 is a C.sub.1 -C.sub.4 alkylene or alkenylene group, &gt;C(CF.sub.3).sub.2, --CO--, --SO.sub.2 --, --S--, --O-- or a valence bond, PA1 R.sup.4 is --Br, --Cl or a C.sub.1 to C.sub.4 alkyl or alkenyl group, and PA1 R.sup.20 is H or alkyl of 1 to 12 carbons. PA1 (1) a polyether epoxide resin E.sup.1 consisting essentially of molecules, each of which is of the formula ##STR3## wherein Q, independently, in each occurence, is ##STR4## n is an integer of from 0 to 40, r is zero, 1 or 2 and, independently in each occurrence; PA1 R.sup.1 is H, methyl or ethyl, PA1 R.sup.2 is --Br, --Cl or a C.sub.1 to C.sub.4 alkyl or alkenyl group, PA1 R.sup.3 is a C.sub.1 -C.sub.4 alkylene or alkenylene group, &gt;C(CF.sub.3).sub.2, --CO, --SO.sub.2 --, --S--, --O-- or a valence bond, and PA1 R.sup.4 is --Br, --Cl or a C.sub.1 to C.sub.4 alkyl or alkenyl group, PA1 R.sup.20 is H or alkyl of 1 to 12 carbons; PA1 (2) E.sup.2, a vicinal epoxide, other than one of formula (a) or (q), which has an EEW (epoxide equivalent weight) within the range of from about 90 to about 2000 and is convertible to a water-dispersible material by reaction with orthophosphoric acid and neutralization with a base, PA1 said reaction being carried out by contacting E.sup.1 and E.sup.2 with an orthophosphoric acid source material and from 0 to 25 molecular proportions of water per molecular proportion of H.sub.3 PO.sub.4 provided by said source material until the fraction of the oxirane groups in E.sup.1 and E.sup.2 converted is at least sufficient to render the resulting mixed product water-thinnable when contacted with a base, the amount of orthophosphoric acid included as such in said source material, or obtainable therefrom by hydrolysis, being such as to provide at least 0.3 P--OH groups per oxirane group, and the mole ratio of E.sup.1 to E.sup.2 epoxides being from about 0.1 to about 100,
The background and significance of the foregoing discovery and the manner of making, neutralizing and using the E.sup.1 /acid reaction products are fully set forth in the above identified companion Application, Ser. No. 853,168, the disclosure of which is incorporated herein by reference. In addition, methods of preparing the neutralized materials are summarized in the present specification.
The foregoing water-thinned products, when freed of water and desalified, can be cured simply by heating. However, the cure times required are longer than are generally desirable for commercial coating operations and curing agents, such as melamine resins, for example, will ordinarily be incorporated with the water-thinned materials when they are applied to the substrate to be coated.
Base-neutralized reaction products of phosphoric acid with various methylol- or lower alkoxymethyl-substituted epoxides have now beeen found to be compatible with the water-thinned, E.sup.1 -derived resin dispersions and to render them rapidly self-converting. It has also been found that the ability of the dispersions to wet various types of substrates can be manipulated to advantage by choice of other substituents in the latter types of curing agents. Other properties of the aqueous dispersions of the neutralized acid/E.sup.1 products, and/or of the cured coatings deriveable therefrom, can be modified to advantage by incorporation of (neutralized) reaction products of phosphoric acid with various other (E.sup.2) type epoxides.